Process for preparing heat exchange component

ABSTRACT

A process of producing continuous strip having at least one fluid passageway with integrally formed fin members, which comprises forming a pattern of weld inhibiting material on a first strip or sheet with a portion of the pattern defining the fluid passageway, and a further portion of the pattern extending along the edge of the strip or sheet defining a fin surface. A second strip or sheet of metal is pressure welded to the first strip or sheet in substantially all areas not containing the weld inhibiting material and the fin surface is formed into a plurality of fin members. The fin members may be formed by cutting, or by a combination of cutting, bending and twisting. Additional fin surface is obtained by separating the strip or sheet at their edge corresponding to the further portion of the pattern of weld inhibiting material. The strip or sheet, in accordance with the invention, may be formed into heat exchangers of any desired shape including a helix, spiral or serpentine.

United States Patent Keith [4 1 May 2,1972

[54] PROCESS FOR PREPARING HEAT EXCHANGE COMPONENT [72] Inventor: NorvalA. Keith, East Alton, I11.

[73] Assignee: Olin Corporation [22] Filed: Feb. 2, 1970 [21] App1.No.:7,729

Related US. Application Data [60] Continuation-in-part of Ser. No.708,463, Dec. 7, 1967, abandoned, and a continuation-in-part of Ser. No.774,577, Nov. 1, 1968, Pat. No. 3,495,657, each is a division of Ser.No. 630,376, Apr. 12, 1967, aban- 3,145,456 8/1964 Johnson 29/1573 V3,178,806 4/1965 Keith ...29/l57.3 V 3,205,563 9/1965 Pauls et a1..29/157.3 V 3,449,552 6/1969 Graves ...29/157.3 A X 3,538,577 11/1970OMalley ..113/118 D X Primary Examiner.lohn F. Campbell AssistantExaminer-Victor A. DiPalma Attorney-Robert H. Bachman and Gordon G.Menzies ABSTRACT A process of producing continuous strip having at leastone fluid passageway with integrally formed fin members, which comprisesforming a pattern of weld inhibiting material on a first strip or sheetwith a portion of the pattern defining the fluid passageway, and afurther portion of the pattern extending along the edge of the strip orsheet defining a fin surface. A second strip or sheet of metal ispressure welded to the first strip or sheet in substantially all areasnot containing the weld inhibiting material and the fin surface isformed into a plurality offin members. The fin members may be formed bycutting, or by a combination of cutting, bending and twisting.Additional fin surface is obtained by separating the strip or sheet attheir edge corresponding to the further portion of the pattern of weldinhibiting material. The strip or sheet, in accordance with theinvention, may be formed into heat exchangers of any desired shapeincluding a helix, spiral or serpentine.

28 Claims, 16 Drawing Figures PATENTEDMAY 21912 3,659,326

SHEET 10F 5 INVENTORZ NORVAL A. KEITH 76/ 7 I BY ATTORNEY PATENTEBMAY 2I972 3,659,326

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ATTORNEY PATENTEIIIIIII 2 I972 3, 659,326

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ATTORNEY PATENTEDMAY 21912 INVENTOR I NORVAL A. /(/FH ATTOfiNEY PROCESSFOR PREPARING HEAT EXCHANGE COMPONENT This application is acontinuation-in-part of US. application Ser. No. 708,463, filed Dec. 7,1967, now abandoned, and 774,577, filed Nov. 1, 1968, now US. Pat. No.3,495,657, granted Feb. 17, 1970, which in turn are divisions of US.Ser. No. 630,376, filed Apr. 12, 1967, now abandoned.

This invention utilizes a process for bonding of at least two sheets ofmaterial in selective areas to provide a fluid passageway or a pluralityof fluid passageways, and bending of the sheets in the edge areas toprovide extended surfaces for heat exchange. The process may utilizewide sheets which are later cut into continuous strips or it may startwith strip material.

For example, a continuous strip of metal may be patterned through acontinuous patterning operation laying down a pattern of weld inhibitingmaterial, and mated with at least one other strip. The strips are theneither hot rolled or cold rolled to bond them together at places wherethere is no weld inhibiting material. Subsequent cold rolling may or maynot be necessary if hot rolling has been used for the bonding. Afterrolling, and annealing if necessary, the strips may be separated alongthe edge of the continuous strip so as to provide a two or more layerfinned surface. This finned surface can then be cut and bent if desired,and the bent portions may be twisted into the desired fin configuration.The so-bent strip can be formed into desired heat exchange shapes, forinstance into a spiral, serpentine, etc.

FIG. 1 is a view of the pattern of the weld inhibiting material to beapplied to a strip of metal according to one process of the invention.

FIG. 2 is a sectional view of the heat exchange component of the presentinvention at one stage of its fabrication.

FIG. 3 is a top view of the heat exchange component of the presentinvention at a different stage in its fabrication.

FIG. 4 is a schematic view of the heat exchange component according tothe present invention.

FIG. 5 is a sectional view along the lines 55 in FIG. 4.

FIG. 6 is a sectional view of a modified heat exchange componentaccording to the present invention.

FIG. 7 is a sectional view of a modified heat exchange componentaccording to the present invention.

FIG. 8 is a sectional view of a modified heat exchange componentaccording to the present invention.

FIG. 9 is a perspective view of a heat exchange component according tothe present invention.

FIG. 10 is a top view of the component of FIG. 9.

FIG. 10A is a top view of a modification of the component of FIG. 9.

FIG. 1 1 is a perspective view of a heat exchange component according toanother embodiment of the present invention.

FIG. 12 is a top view of the component of FIG. 11.

FIG. 13 is a perspective view of a heat exchange component according toanother embodiment of the present invention.

FIG. 14 is a top view of the component of FIG. 13.

FIG. 15 is a perspective view showing the fabrication of a wide sheet inaccordance with this invention.

The method of processing in accordance with this invention is based onthe Grenell Pat. No. 2,690,002, granted Sept. 28, I954, assigned to theassignee of the instant invention. Briefly, two or more sheets or stripsof metal, which for example, may be aluminum, aluminum alloys, copper,copper alloys, steel, or other suitable metal, are first cleaned andbrushed. Next, an appropriate pattern of weld inhibiting material isformed on a surface of at least one of the sheets or strips of metal.For a multisheet or strip article, weld inhibiting material might beapplied to more than one of the sheets or strips, depending upon thepattern desired.

As shown in FIG. 1, using a two-strip article as an example, the weldinhibiting pattern may comprise two stripes l0 and 11. Stripes 12, 13and 14 are provided which contain no weld inhibiting material. However,in the embodiment of the invention, external stripes 15 and 16 areprovided with weld inhibiting material. If desired, the weld inhibitingstripes l0 and 11 may merge at 17 and 18 to provide an inlet portion 19.However, if desired, the stripes 10 and 11 may be so designed as toconstitute a repeatable pattern and may form conduits of varying sizes.Also, if desired, the patterns 10 and 11 may merely extend to the edgeof the strips as shown at 10a and 1 1a.

After application of the pattern, the strips are bonded together atplaces on their surfaces which do not contain weld inhibiting material.This can be done by either hot rolling or cold rolling.

I-Iot rolling and annealing temperatures will vary with the metals beingprocessed. For example, aluminum sheets can be processed by heating thesheets to a temperature of between approximately 800 and 1,000 F,preferably approximately 900 and 950 F. After heating, the strips arehot worked to a reduction in gage of at least 60 percent. However, agreater amount of reduction will improve the bond and a reduction ofapproximately 65 percent is preferred.

The bonding can also be done by cold rolling, in which a reduction offor example, 70 percent is achieved in the first pass. A second coldreduction pass may or may not be used. However, if only one pass isused, the reduction may be even greater than 70 percent. The gage mustbe reduced by approximately 4 to 1.

' As is known to one skilled in the an, of both hot and cold rolling,such process difficulties as control of camber must be controlled byknown methods.

If hot rolling is used, following the hot reduction, the bonded stripsare preferably cold rolled, for example, to a reduction of about 35percent and then annealed. As an example, for aluminum and aluminumalloys sheets, a temperature of approximately 650 to l,00O F ispreferably used. If there has been no cold rolling, annealing is notnecessary. Of course, if all cold reduction was used in the rolling,annealing at the indicated temperatures is necessary. The bondedcomposite may be slit to trim ragged edges prior to or subsequent toannealing and then sheared to the desired length after annealing. Ifdesired, the bonded composite may be cut in the other direction toprovide long thin strips. The sheared composite may then be inflated.For example, an inflation pressure of from approximately 500 to 3,000p.s.i. may be used. Preferably, however, inflation is left for a laterstage in the processing so the inflated tube will not be damaged duringsuch processing. Normally, the inflation follows the formation of thefins.

If the inflation operation were performed at this point in the process,the resultant article would have a shape as shown in FIGS. 2 and 3. Thepatterns of weld inhibiting material 10, ll, 17, 18 and 19 would haveresulted in corresponding tubular portions 20, 21, 27, 28 and 29. Thesections 12, 13 and 14 would have resulted in bonded portions 22, 23 and24, respectively. If weld inhibiting material was placed on sections 15and 16 in FIG. 1, unbonded portions 25 and 26 will still contain theweld inhibiting material as shown in FIG. 2.

The articles shown in FIGS. 2 and 3 may or may not be cut. If cutting isdone, it takes place in longitudinal edge portions 25 and 26, resultingin a plurality of slitted portions 35 and 36. The cutting operation canbe done by means of conventional equipment.

If cutting has been done, the cut edge portions may then be bent to adesired fin configuration as shown in FIGS. 4 and 5. It will be apparentthat the portions 35a, 35b, 35c and 35d, and 36a, 36b, 36c and 36d havebeen bent to a varying extent.

The extent to which the cut portions are bent is a matter of design. Forexample, as shown in FIG. 6, the portions 35a and 35d and 36a and 36dhave been bent even further in this embodiment than was shown in FIG. 5.

In FIG. 7, cut edge portions 35b and 350 and 36b and 360 have not onlybeen bent but have been rotated or twisted, approximately percent, whilethe cut edge portions 35a and 35d and 36a and 36d have been bent but notrotated.

If weld inhibiting material was not placed upon either of the sections15 and 16 in FIG. 2 according to another embodiment of the invention,portions 25 and 26 may be cut as shown in FIG. 3 and then each cutportion may be bent and/or rotated a desired amount to form fin area.

For example, in FIG. 8, every other out portion 35a, 36a, has beenrotated upwardly, while every other cut portion 35b, 36b has beenrotated downwardly.

Whether or not weld inhibiting material has been applied to the edgeportions, the extent of the bending and rotating of the members willvary with the design and application and it will be apparent that manyother designs of bending and rotating than those illustrated may beemployed within the scope of the present invention.

The drawings in the present application show, as an example, atwo-conduit unit in FIGS. 1 through 6. However, in many applicationsonly one conduit will be used, as illustrated in FIGS. 7 and 8. Theconduit 30 and welded portions 33 and 34 are obtained by using anappropriate weld inhibiting pattern and following a technique previouslydescribed in regard to a two-conduit pattern. It is apparent that anynumber of conduits may be provided within the scope of the presentinvention, by providing the appropriate weld inhibiting pattern upon theappropriate sheets.

Varying lengths of the heat exchange components shown in FIG. 4 may beproduced. For many applications it is desirable to produce long lengthsof such components. One such embodiment is shown in FIGS. 9 and 10. Thearticle 49 has fin sections 45, 46, 47 and 48, conduit sections 40 and41, and welded portions 42, 43 and 44. In FIG. 9, the fin sections 45,46, 47 and 48 are shown as having been formed by cutting prior to beingbent. However, it is to be understood that these fin sections could alsobe made by omitting the cutting and merely bending the cut sheets.

In FIG. 9, it is seen that the article has been bent into a spiral. Thisspiral unit can be used in forced air evaporators, such as thosepresently used in forced air refrigerators. If desired, as shown in FIG.A, the spiral may be wound more tightly to avoid the center C in FIG.10, to form the article 4911.

In FIG. 9, it will be apparent that a transverse section appears wherethe numbers 40, 41 and 45-48 appear. In this transverse cross section,the major axis of the component passes through the bonded portions whichare on either side of passageways 40 and 41. It will be apparent thatthe major axis in which the shape. is bent and the major axis of thecomponent in a transverse cross section are parallel in FIGS. 9, 10 and10A.

FIGS. 11 and 12 show a structure similar to that shown in FIG. 9. Thearticle 59 again has conduit portions 50 and 51 together with weldedportions 52, 53 and 54. The fins 55, 56, 57 and 58 may be formedaccording to either of the methods described in regard to FIG. 9 (withor without cutting). The basic difference between the embodiments shownin FIGS. 11 and I2 and that shown in FIGS. 9 and 10 is that the axis ofthe component of which the spiral is formed is clearly different. Thearticle 59 has the advantage that it can be used as either an airevaporator or a condenser heat exchanger with air flow across theconvolutions.

FIGS. 13 and- 14 show an article 69 again having conduit portions 60 and61 together with welded portions 62, 63, 64 and fins 65, 66, 67 and 68.However, the article 69 is bent in a shape of a figure eight so as toprovide more surface area in the center section of the unit.

FIG. 14 is a top view of FIG. 13 and includes a starting line S and adotted finish line F in tracing the path of the figure eight shown inFIG. 14.

It will be apparent in the embodiment shown in FIGS. 11 and 12 and 13and 14 that in a transverse cross sectiomthe major axis of the componentand the axis of the shape into which the article is bent areperpendicular.

It will be apparent to those skilled in the art that the heat exchangecomponents of the present invention can be bent and/or wound into manyother shapes to suit particular heat exchange applications.

It will also be apparent that the conduit portions must be appropriatelyconnected to sources of the heat exchange medium to be passedtherethrough by couplings known to those skilled in the art. Forinstance, soldered or brazed couplings may be used, or in someinstances, rubber hose-type couplings can be used. The couplings areknown in the art and do not form a part of the present invention exceptinsofar as said couplings are associated with the heat exchangecomponents of the present invention.

In accordance with another embodiment of the instant invention, thecontinuous strip can be produced from wide sheet metal which is laterslit into the strips 101 of the desired width. Referring to FIG. 15,there is shown a first sheet 102 which is wide enough to include aplurality of strip areas 103 with each strip area containing a suitablepattern of weld inhibiting material 104. The pattern 104 in each striparea 103 includes at least one portion 105 corresponding to aninflatable fluid passageway and may contain a plurality of portions 105.A further portion 106 of the pattern 104 in each strip area 103 isusually included which extends along the longitudinal edges of theresulting strip 101 so that the sheets I02, 107 of the strip 101 may bebent apart at the edges as set forth above. After the sheet 102 has beenpatterned, a second sheet 107 is pressure welded to it in the manner setforth above. The two sheets 102 and 107 become bonded together in allareas which do not include weld inhibiting material. The strip 101 isthen formed by slitting or cutting the sheet along lines 108corresponding to the boundary of each strip area 103. The resultingstrips 101 may then be treated in accordance with the processing notedabove, so as to form the desired heat exchange component. The wide sheet100 of this embodiment may be made in very long lengths which may becoiled for ease in handling, and the strips 101 slit or cut from thesheet 100 may also be coiled prior to further processing.

If desired, a control tube pattern of weld inhibiting material inaccordance with the process disclosed in copending US. application Ser.No. 5,548, filed Jan. 26, 1970, by N.A. Keith, assigned to the assigneeof the instant application, may be included in a fixed relationship tothe other patterns 104 in the sheet 100 so that the sheet may be slitemploying the process and apparatus of the copending application. It isalso to be understood that the pattern of weld inhibiting material maybe formed by any desired technique including the process disclosed inapplication U.S. Ser. No. 723,055, filed Apr. 22, 1968, by N.A. Keith,assigned to the assignee ofthe instant invention.

It is to be understood that the invention is not limited to theillustrations described and shown herein, which are deemed to be merelyillustrative of the best modes of carrying out the invention, and whichare susceptible of modifications of form, size, arrangement of parts anddetail of operation. The invention rather is intended to encompass allsuch modifications which are within the spirit and scope of theinvention as set forth in the appended claims.

What is claimed is:

l. A process for producing finned strip having at least one inflatablefluid passageway with integrally formed fin members comprising:

providing at least one first strip of metal;

forming a first pattern of weld inhibiting material on said first strip,defining at least one inflatable fluid passageway;

forming a second pattern of weld inhibiting material upon at least aportion of at least one longitudinal edge of said first strip extendingsubstantially along the length of said edge, said second pattern beingspaced from said first pattem and defining a fin surface;

placing at least one second strip of metal upon said first bonding saidsheets together at substantially all portions not containing weldinhibiting material; and

forming said fin surface into a plurality of fin members.

2. A process as in claim 1 which includes the step of: inflating saidpassageway to form an unobstructed tubular passageway completely definedby said first and second strips, and adapted to contain a heat exchangemedium.

3. A process as in claim 2 wherein the forming of said fin surface intoa plurality of fin members includes separating said strips of metal fromeach other at said second pattern at said at least one edge to formadded fin surface in heat exchange relationship with said at least oneinflatable fluid passageway.

4. A process as in claim 2 wherein the forming of said fin membersincludes the step of cutting said fin surface into a plurality of finmembers. I

5. A process as in claim 3 wherein the forming of said fin membersincludes the step of cutting said fin surface into a plurality of finmembers.

6. A process as in claim 2 wherein the fin members are bent a desiredamount.

7. A process as in claim 6 in which adjacent fin members are bent todiffering extents.

8. A process as in claim 6 wherein the fin members are both bent andtwisted.

9. A process as in claim 2 in which said strip has a plurality ofpassageways.

10. A process as in claim 2 wherein said strip is formed into a heatexchange component of desired shape.

11. A process as in claim 10 in which said shape is a helix.

12. A process as in claim 10 in which the shape is a spiral.

13. A process as in claim 10 in which the shape is a serpentine.

14. A process as in claim 2 wherein an identifying mark is placed uponone of the strips after the patterning operation, said mark beingutilized to subdivide the bonded sheets.

15. A process for producing strip having at least one inflatable fluidpassageway with integrally formed fin members comprlSlIlg.

providing at least one sheet of metal, said sheet of metal containing aplurality of strip areas;

forming a first pattern of weld inhibiting material on said first sheet,defining at least one inflatable fluid passageway in each of said stripareas;

forming a second pattern of weld inhibiting material upon at least aportion of at least one longitudinal edge of each of said strip areas,said second pattern extending substantially along the length of saidedge, said second pattern being spaced from said first pattern anddefining a fin surface;

placing at least one second sheet of metal upon said first sheet;

bonding said sheets together at substantially all portions notcontaining weld inhibiting material;

forming said bonded sheets into a plurality of strips, with each stripcorresponding to one of said strip areas; and forming said fin surfaceinto a plurality of individual fin members.

16. A process as in claim 15 which includes the step of inflating saidat least one passageway in said strips to form an unobstructed tubularpassageway adapted to contain a heat exchange medium.

17. A process as in claim 16 wherein the forming of said fin surfaceinto a plurality of fin members includes separating said sheets of metalfrom each other in each of said strips at said second pattern in said atleast one edge to form added fin surface in heat exchange relationshipwith said at least one inflatable fluid passageway.

18. A process as in claim 16 wherein the forming of said fin membersincludes the step of cutting said fin surface into a plurality of finmembers.

19. A process as in claim 17 wherein the forming of said fin membersincludes the step of cutting said fin surface into a plurality of finmembers.

20. A process as in claim 16 wherein the fin members are bent a desiredamount.

21. A process as in claim 20 in which adjacent fin members are bent todiffering extents.

2. A process as in claim 20 wherein the fin members are both bent andtwisted.

23. A process as in claim 16 in which each of said strips has aplurality of passageways.

24. A process as in claim 16 wherein each of said strips is formed intoa heat exchange component of desired shape.

25. A process as in claim 24 in which said shape is a helix.

26. A process as in claim 24 in which the shape is a spiral.

27. A process as in claim 24 in which the shape is a serpentine.

28. A process as in claim 16 wherein an identifying mark is placed uponone of the sheets after the patterning operation, said mark beingutilized to subdivide the bonded sheets.

1. A process for producing finned strip having at least one inflatablefluid passageway with integrally formed fin members comprising:providing at least one first strip of metal; forming a first pattern ofweld inhibiting material on said first strip, defining at least oneinflatable fluid passageway; forming a second pattern of weld inhibitingmaterial upon at least a portion of at least one longitudinal edge ofsaid first strip extending substantially along the length of said edge,said second pattern being spaced from said first pattern and defining afin surface; placing at least one second strip of metal upon said firststrip; bonding said sheets together at substantially all portions notcontaining weld inhibiting material; and forming said fin surface into aplurality of fin members.
 2. A process as in claim 1 which includes thestep of: inflating said passageway to form an unobstructed tubularpassageway completely defined by said first and second strips, andadapted to contain a heat exchange medium.
 3. A process as in claim 2wherein the forming of said fin surface into a plurality of fin membersincludes separating said strips of metal from each other at said secondpattern at said at least one edge to form added fin surface in heatexchange relationship with said at least one inflatable fluidpassageway.
 4. A process as in claim 2 wherein the forming of said finmembers includes the step of cutting said fin surface into a pluralityof fin members.
 5. A process as in claim 3 wherein the forming of saidfin members includes the step of cutting said fin surface into aplurality of fin members.
 6. A process as in claim 2 wherein the finmembers are bent a desired amount.
 7. A process as in claim 6 in whichadjacent fin members are bent to differing extents.
 8. A process as inclaim 6 wherein the fin members are both bent and twisted.
 9. A processas in claim 2 in which said strip has a plurality of passageways.
 10. Aprocess as in claim 2 wherein said strip is formed into a heat exchangecomponent of desired shape.
 11. A proceSs as in claim 10 in which saidshape is a helix.
 12. A process as in claim 10 in which the shape is aspiral.
 13. A process as in claim 10 in which the shape is a serpentine.14. A process as in claim 2 wherein an identifying mark is placed uponone of the strips after the patterning operation, said mark beingutilized to subdivide the bonded sheets.
 15. A process for producingstrip having at least one inflatable fluid passageway with integrallyformed fin members comprising: providing at least one sheet of metal,said sheet of metal containing a plurality of strip areas; forming afirst pattern of weld inhibiting material on said first sheet, definingat least one inflatable fluid passageway in each of said strip areas;forming a second pattern of weld inhibiting material upon at least aportion of at least one longitudinal edge of each of said strip areas,said second pattern extending substantially along the length of saidedge, said second pattern being spaced from said first pattern anddefining a fin surface; placing at least one second sheet of metal uponsaid first sheet; bonding said sheets together at substantially allportions not containing weld inhibiting material; forming said bondedsheets into a plurality of strips, with each strip corresponding to oneof said strip areas; and forming said fin surface into a plurality ofindividual fin members.
 16. A process as in claim 15 which includes thestep of inflating said at least one passageway in said strips to form anunobstructed tubular passageway adapted to contain a heat exchangemedium.
 17. A process as in claim 16 wherein the forming of said finsurface into a plurality of fin members includes separating said sheetsof metal from each other in each of said strips at said second patternin said at least one edge to form added fin surface in heat exchangerelationship with said at least one inflatable fluid passageway.
 18. Aprocess as in claim 16 wherein the forming of said fin members includesthe step of cutting said fin surface into a plurality of fin members.19. A process as in claim 17 wherein the forming of said fin membersincludes the step of cutting said fin surface into a plurality of finmembers.
 20. A process as in claim 16 wherein the fin members are bent adesired amount.
 21. A process as in claim 20 in which adjacent finmembers are bent to differing extents.
 22. A process as in claim 20wherein the fin members are both bent and twisted.
 23. A process as inclaim 16 in which each of said strips has a plurality of passageways.24. A process as in claim 16 wherein each of said strips is formed intoa heat exchange component of desired shape.
 25. A process as in claim 24in which said shape is a helix.
 26. A process as in claim 24 in whichthe shape is a spiral.
 27. A process as in claim 24 in which the shapeis a serpentine.
 28. A process as in claim 16 wherein an identifyingmark is placed upon one of the sheets after the patterning operation,said mark being utilized to subdivide the bonded sheets.